CHECK ENGINE Light just came on after traveling through flooded streets

We had brutal rain in south Texas this afternoon (5.6" in about an hour), and the streets were flooded. Traveling through water up to the axles (2008 Outback) was inevitable... unfortunately. Obviously the engine compartment must have gotten really wet. However, there doesn't seem to be any ill effects: the engine sounds fine, transmission shifts normally, no smoke, etc...

The problem is, my check engine light came on and the cruise control indicator started flashing. Surely there must be others with a similar experience. Should I be overly concerned [about the check engine light]? Also, should I consider any maintenance on parts that the water may have damaged?

Do you have an OBDII code reader, or access to borrow one? That code would be useful in troubleshooting the issue.

You can use WD40 to clean, the WD in the name actually stands for Water Displacing.

Not on any rubber parts, though, which won't like the contact with any petroleum products.

If the plugs went under water I'd probably replace those and the spark plug wires while you're at it. There could be water in those boots that may never evaporate if they're sealed up in there.

We went driving in the Pine Barrens and this particularly crazy guy in a Subaru XT6 drove through deep water and even got water in his intake. Some ad-hoc mechanics removed his plugs, sprayed in WD40, ran the starter a few times to get the water out the engine, and voila! It actually ran again. It was wild.

He did lose his clutch that day, though.

I would go ahead and change all your fluids, to be safe. Flush the brakes, clutch, trans, front diff, rear diff, engine oil, and radiator. Any or all of those could be contaminated if they were under water long enough.

I drove the car about a mile this morning to make sure everything was on the up and up. The Check Engine light was still on, but the car sounded like it was running fine, and there was no performance problems.

This afternoon, while running errands, the Check Engine light had shut off and it seemed to be running just fine. However, twenty minutes later, while parked, I smelled burning antifreeze. In the 5 minutes it took me to get home, the AC stopped blowing cold air, and the engine was beginning to overheat (needle wasn't burried).

Sure enough, when I got home, there was a steady drip from the radiator (there was also a mist of antifreeze on the ceiling of the hood as if there was a burst). So clearly the radiator has a huge leak. But PLEASE tell me my engine is fine. I ask this because when it started to overheat, I began to hear a knock when I'd accelerate.

Any thoughts as to if this might be a warranty issue? Also, the nearest Subaru dealer is 2.5 hours away... how does the Subaru community feel about taking Subaru's in to non-dealerships for repairs? I only ask because I'm a new Subaru owner... had the car for about 2 months.

It is possible that there is a cracked block issue here. I very much doubt, given the circumstances, that this is a something that would be warranty-related unfortunately. If you have experienced independent mechanics available, there is no reason not to let one inspect the situation.

One more detail: I don't know if it makes a difference or not, but I don't think any water got into the engine. I'm basing this off of the fact that when I checked the oil, it looked healthy (i.e., not milky).

If it's new you may have the Subaru roadside assistance. Check the owner's manual. They can probably cover the first 100 miles towing for free.

I'd call 800-SUBARU3 and ask for their advice, also.

This is a bummer, the car is so new.

Whether they cover it or not will depend on what exactly happened, I guess. I'm suer they'll find signs of water so be honest with them, but then again a splash of water didn't necessarily cause all the damage. I hope not.

It is so hard to say at this point. I used to drive my '96 Outback through some serious puddles. In the springtime here we get many streets and parking lots flooded due to frozen storm drains and massive meltoff over the course of a few days to a week in April (or sometimes May). Some of the puddles are 100 yards or more across and deep enough that the exhaust was underwater (gurgle gurgle gurgle....). I never had any problems at all. Usually that level of water causes problems when one tries to go too fast and sucks water into the intake.

I know it's been awhile since the last post but I thought I'd update since future owners may find this info useful.

After driving through flooded streets, my 2008 OB developed an overheating problem. Specifically, after about 5 minutes of driving, when the engine temp gauge is at half, I begin to hear a "knocking" noise that sounds almost like a diesel engine. Then, the temperature gauge shoots up... after that, I don't know because I've only driven it a few times since the overheating problem developed.

The good thing is; I don't think there are any major issues with the engine/head gasket/transmission/etc. In earlier posts I had been concerned with damage to the engine but I've ruled that out as I can't re-create the noise when the vehicle is in neutral (after it has overheated). My impression is that water caused the failure of some electric component which is important in cooling the engine (NOTE: I AM NOT A MECHANIC).

The vehicle is still under the manufacturers warranty so I'll be calling road side assistance for a tow in to San Antonio, the nearest Subaru dealership. If its covered under warranty great, if not, I feel better about having it repaired by a Subaru mechanic. I'll keep you all posted with results in the coming days.

Thanks again for all the help; it is reassuring that there is a dedicated and knowledgeable community of Subaru owners willing to share their experience and $0.02. The Best,

Just heard from the Subaru dealership working on my OB. Turns out there was a decent sized hole in the radiator. He speculates that the fan blade impacted the radiator.

I asked him about the knocking noise that is produced after it overheats and his impression was that it was probably nothing to lose sleep about (unless one drove while it was overheated for a prolonged period of time).

Keep us posted about how it continues to run. You might also consider changing the oil in light of everything that happened, if you have not done so already, just to ensure it is giving your engine the protection it needs.

I think you handled the whole situation very well. Hopefully you have many years of enjoyment from this vehicle yet to come!